Pest of the Month

by: Gary H. Brinen, Commercial Horticulture Agent

Giant Whitefly (aleurodicus dugesii)

This whitefly is native to Mexico, set feet first on U.S. soil in Texas, and appeared in Volusia County in 1996. If has spread and now we have seen it here it here in Gainesville landscapes on hibiscus this summer.

This whitefly is three times larger than any other whitefly. It's wings are white with some dark spots. Females lay eggs on leaf undersides in distinctive spirals. Adults and larva congregate in great numbers and really cause an mess as they feed and exude honeydew. Larva serret long, white wax filaments that hang from under the infested leaves. Their feeding can cause plants to decline. Their life cycle is 35 days.

So far, in Florida, Giant Whitefly has mainly attacked Hibiscus species but has been found on citrus, beauty berry, glory bower, coleus, mulberry, banana, flame vine, caesar's weed and frost weed. I recently saw it on the herb, basil.

In California, it is reported to attack 43 genera and 35 plant families. They include bamboo, begonia, boxwood, canoa, colacasia, ginger, gladiolus, ivy, lantana, sweet gum, mulberry, nandina, orchid, geranium, pitto sparum, poinsettia, solandra, solanum, vitex and water lilies.

The Department of Agriculture has been releasing a parasitic wasp wherever the whitefly is spotted and have hopes that it will keep infestations down. In the absence of parasitized whiteflies, take an integrated approach to control.

Other biological agents include green lace wings, synphid flies and lady beetles. First, inspect frequently to spot the egg spirals and then remove those infested leaves. Chemical controls include Avid, Azatin, Talstar or Attain, Endosulfin or Thiodan, Tame, Sunspray oil, Marathion or Merit, M-Pede soap, Enstar II, Endeavor, Distance IGR or Pyrigro, and Plant fume 103.

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